Alvarez only turned 17 last month, but has already attracted reported interest from Lazio after a starring performance at the CONMEBOL U-17 South American Championship in Chile last month.
Alvarez, who plays in the second division for Callejas, will join up with the squad tomorrow with players due to arrive over the course of the weekend as local leagues come to a close.
Goalkeepers: Carlos Arias (Bolivar), Carlos Lampe (Universitario)
Defenders: Abdon Reyes (Bolivar), Enrique Parada (San Jose), Ronald Raldes (Cruz Azul), Luis Gatty Ribeiro (Real Potosi), Ronald Rivero (Universitario), Luis Gutierrez (Hapoel Ironi Kiryat Shmona), Edhemir Rodríiuez (Real Potosi), Miguel Hoyos (Bolivar), Juan Manuel Pena (Celta)
Midfielders: Didi Torrico (Wilstermann), Julio Cesar Hurtado (Aurora), Jaime Robles (Blooming), Ignacio Garcia (Bolivar), Mauricio Saucedo (Universitario), Alex da Rosa (San Jose), Walter Flores (Bolivar), Joselito Vaca (Oriente Petrolero), Leonel Reyes (Bolivar), Ronald Garcia (Aris Thessaloniki), Pablo Escobar (Santo Andre)
Forwards: Gerardo Yacerotte (Real Potosi), Diego Cabrera (Medellin), Marcelo Martins (Shakhtar Donetsk), Gilbert Alvarez (Callejas)